The invention relates to an internal-combustion engine having a cylinder block and crankcase comprising a case structure which has at least two cylinders or cylinder bank rows arranged in a V-shape with respect to one another, an endless drive extending on a face of the cylinders or cylinder bank rows, which drive comprises a timing chain, for connecting a crankshaft with camshafts arranged in cylinder heads, the timing chain being covered by a timing drive cover.
From Japanese Patent Document JP 8-200088 A, a timing chain case for an internal-combustion engine is known which has an interior rib structure by way of which, among other things, an oil guiding duct is formed which is directed to the crankshaft and by means of which the oil splashing around in the chain case is collected.
It is an object of the invention to provide devices for cylinders preferably arranged in a V-shape with respect to one another, by which devices the lubricating oil carried along by a timing chain for the camshaft drive is returned in a targeted manner to the oil pan of the internal-combustion engine.
This object is achieved in that the timing drive cover, or the case structure situated opposite the timing drive cover, has a ribbing by way of which a targeted separation or return takes place of oil carried along by the timing chain in a direction of the cylinder heads.
As a result of the ribbing according to the invention, a portion of the lubricating oil carried along by the timing chain in the direction of the cylinder heads is wiped off at several points within the timing chain case and is returned in a targeted manner to the oil pan of the internal-combustion engine. As a result of the controlled separation of the lubricating oil, the cross-section, among others, in the timing chain case can be kept free for the flowing-off of the crankcase gases, the so-called blow-by gases.
Further advantageous developments and improvements of the internal-combustion engine according to the invention can be achieved as a result of the measures indicated in the subclaims.
By way of a U-shaped deflection rail, the end of the timing chain extending between the two cylinder heads and above the crankshaft is guided closely along a main rib. The lubricating oil carried along by the timing chain is carried along on the main rib to an oil return flow opening arranged in the apex area of the main rib, before it returns by way of the return flow opening in the oil pan of the internal-combustion engine.
The main rib is adjoined on the left and on the right by one ribbing structure respectively which consists of several partial ribs and, in the case of which, the individual partial ribs are used as an oil guiding duct or for wiping off the lubricating oil carried along by the timing chain.
The ribbing is advantageously arranged on the interior side of the timing drive cover and therefore simultaneously contributes to the reinforcement of the timing drive cover.
An embodiment of the invention is illustrated in the drawings and will be described in detail in the following.